s390/keyboard: use memdup_user_nul()
Use memdup_user_nul to duplicate a memory region from user-space
to kernel-space and terminate with a NULL, instead of open coding
using kmalloc + copy_from_user and explicitly NULL terminating.
Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
[heiko.carstens@de.ibm.com: remove comment]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/keyboard.c b/drivers/s390/char/keyboard.c
index ef04a9f..7b9c50a 100644
--- a/drivers/s390/char/keyboard.c
+++ b/drivers/s390/char/keyboard.c
@@ -438,18 +438,9 @@
return -EFAULT;
if (len > sizeof(u_kbs->kb_string))
return -EINVAL;
- p = kmalloc(len, GFP_KERNEL);
- if (!p)
- return -ENOMEM;
- if (copy_from_user(p, u_kbs->kb_string, len)) {
- kfree(p);
- return -EFAULT;
- }
- /*
- * Make sure the string is terminated by 0. User could have
- * modified it between us running strnlen_user() and copying it.
- */
- p[len - 1] = 0;
+ p = memdup_user_nul(u_kbs->kb_string, len);
+ if (IS_ERR(p))
+ return PTR_ERR(p);
kfree(kbd->func_table[kb_func]);
kbd->func_table[kb_func] = p;
break;